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'is' versus try cast with null check
...'t need to be cast again
...
}
C# 7.0 supports a more compact syntax using pattern matching:
if (myObj.myProp is MyType myObjRef)
{
...
}
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How do I change the default port (9000) that Play uses when I execute the “run” command?
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Play 2.x
In Play 2, these are implemented with an sbt plugin, so the following instructions are really just sbt tasks. You can use any sbt runner (e
In Play 2, these are implemented with an sbt plugin, so the following are re...
Call by name vs call by value in Scala, clarification needed
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The example you have given only uses call-by-value, so I will give a new, simpler, example that shows the difference.
First, let's assume we have a function with a side-effect. This function prints something out and then returns...
string.charAt(x) or string[x]?
Is there any reason I should use string.charAt(x) instead of the bracket notation string[x] ?
6 Answers
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Putting an if-elif-else statement on one line?
...ould most likely violate PEP-8 where it is mandated that lines should not exceed 80 characters in length.
It's also against the Zen of Python: "Readability counts". (Type import this at the Python prompt to read the whole thing).
You can use a ternary expression in Python, but only for expressions...
How to echo shell commands as they are executed
In a shell script, how do I echo all shell commands called and expand any variable names?
13 Answers
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What are Aggregates and PODs and how/why are they special?
...d only in PODs then you must first read the definition, implications, and examples of aggregates and then you may jump to PODs but I would still recommend reading the first part in its entirety. The notion of aggregates is essential for defining PODs. If you find any errors (even minor, including gr...
Fastest way to convert string to integer in PHP
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I've just set up a quick benchmarking exercise:
Function time to run 1 million iterations
--------------------------------------------
(int) "123": 0.55029
intval("123"): 1.0115 (183%)
(int) "0": 0.42461
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nonlocal keyword in Python 2.x
...local variable but it seems like this keyword is not available in python 2.x. How should one access nonlocal variables in closures in these versions of python?
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How to check if a number is a power of 2
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There's a simple trick for this problem:
bool IsPowerOfTwo(ulong x)
{
return (x & (x - 1)) == 0;
}
Note, this function will report true for 0, which is not a power of 2. If you want to exclude that, here's how:
bool IsPowerOfTwo(ulong x)
{
return (x != 0) && ((x &...